Who is behind this site?

This web site belongs to and is maintained by:

Christoph Haas
Oldesloer Straße 14a
23843 Rümpel


Data privacy

  • This web site is served by a Debian server in a data center in Berlin/Germany.
  • I have sole root access to the server. All your HTTP requests point to one Debian server that is located in a data center in Berlin/Germany.
  • All assets like images and fonts are served directly from this site. Your browser will not be asked to request information from other services like Google’s fonts or Google Analytics. So no data is shared.
  • Every HTTP request is recorded in a standard Apache access log file to help me track down technical problems with this site. Every log entry gets removed automatically after 14 days.
  • I run an instance of Matomo (formerly known as Piwik) on the same server to track what my readers are doing in this web site. Matomo sets a cookie in your browser and stores your actions in a database. If you object to that kind of tracking please enable the “do not track” feature in your web browser. That way none of your actions will be remembered by Matomo.
  • To count how many people read a certain article a plugin sets a cookie to avoid counting twice. The cookie has a lifetime of 24 hours.
  • None of the information I gather is shared with anyone.


45 thoughts on “Imprints/Privacy”

  1. Thank you so much for your great work!

    But unfortunately, there are *BSD users as well. Would you please make an OpenBSD section?

    I'll soon send some donations!

    Best wishes.

    1. Christoph Haas

      Thanks for the kind feedback. Honestly I've spent the past nearly 10 years usind and supporting Debian. What are you missing that you find OpenBSD specific?

  2. Workaround-Fan

    Thank you so much for your great work! I hope you continue this site forever and ever. 🙂

  3. Rene Medina

    English is not my mother language but, shouldn’t “On you can save my findings in numerous articles.” be “On you can find my savings in numerous articles.”?

  4. Grafix Criticism

    Hi, thanks for your great site, the ISP Email tutorial is a great reference. However, there is some room for improvement: your website has a very ugly font, it is near to unreadable. I do not understand why since a few years some smaller websites suffer from this ugly-font desease, but it seems to be something that has to do with bad browser rendering and not building websites for all browsers etc. I am using Win XP / Win 7 and Debian / Ubuntu, but this webiste fonts look scrumbled and broken on all systems, also I tried several different machines, same result.

    The font rendering is excelent for other programs and most other websites, only a few (small) websites suffer from this.

    You can see a screenshot of how your site looks here:

    This is not jpeg artifacts destroying the font rendering in this picture! The site looks like this on the screen!

    Another annoyance:
    The last line in this comment field is not fully visible while writing – see this screenshot:

    No, I did not move the scrollbar up, I am just writing, just try it yourself.

    Maybe it is better to ditch drupal – there are much better tools out there that give no headache, like e.g.

    1. Christoph Haas

      Thanks for the feedback. To be honest I'm browsing my own page from two different computers and operating systems and everything looks right. I'm using a standard Google font that is loaded from Drupal. So I can't explain why the rendering is so crappy for your.

      Drupal sucks big time – I totally admit that. If there was once decent open-source CMS I'd switch instantly. I've tried Joomla and Typo3 recently (just for a few hours) and wasn't convinced either. Some people even keep telling me they use WordPress as a CMS which is completely ridiculous.

      I'm just watching the Docpad screencast out of curiosity. So far it looks more like a Javascript-based web framework. As I'm rather dealing with lots of content I'd prefer a CMS. If I started to hand-craft I'd probably consider doing that with Rails. But thanks for the hint.

      1. I wonder if you’ve come to a conclusion. Being in a similar situation I’m about to try BrowserCMS 3.0 which is a Rails app and looks very promising. Actually, it comes as a gem plugged into an otherwise empty application. Another point for me is i18n.

      2. Brolin Empey

        “Some people even keep telling me they use WordPress as a CMS which is completely ridiculous.”

        Apparently you have switched to WordPress in the 4 years and 5 months between you posting the above comment (“2013-02-23 at 18:30”) and me posting this comment?

        1. Christoph Haas

          Hehe, nice one. Indeed I was hating WordPress back then because it was very limited regarding its feature set. And even today I dream of writing a CMS that would be worth the name. But considering the pain I had with Drupal (missing WYSIWTF editor, broken updates all the time) even WordPress became a better choice for me. I still manage a Drupal site and I hate it. Consider it more the lesser of two evils. 🙂

      3. Toni Mülller

        OpenBSD comes with its very own email server software, which is quite unlike any other I’ve seen so far. I haven’t yet dug into it, though.

        As for a CMS, I recommend taking a look at Wagtail.

    2. I use WinXP (IE8), Win7(IE8, FF, Safari) and MacOSx 10.6.8 (Safari) on different hardware. This site and its fonts looks perfect on all systems, no problem.


    3. Hello guys,

      in my opinion it is a problem with the font rendering. For instance in Windows XP this rendering (called “Clear Type”) is disabled by default and you have to enable it manually (Rightclick your Desktop and then you have to look through the options). Somehow it seems that you have disabled this rendering on your other operating systems, too. You have to find the options to enable it yourself depending on your desktop environment (GNOME, KDE, Unity, etc.).

      For further information check:

      Maybe this is not the reason for that scrambled font but it looks like it.

      The question if this is true is: Why is it disabled? Some browser have their own rendering engine. I hope I could help a bit.

  5. zwiebelchen


    first of all: your website is great !

    But I’d be a little happier if you could update your mailserver guide to match Debian Wheezy.

    Thanks !

    1. Christoph Haas

      Thank you. Yes, I know that I'm late again with updating the tutorial. However I have to finish a paid project first. I hope to get it done in August. 🙁

      1. Wheezy tutorial would be great. Thanks so much for investing your time in this, it’s been an invaluable help for me in the past years!

      2. Dear Cris,

        if you need any help to write, test or anything else, I will be glad to assist you!
        So please, just ask 🙂

        Thank you for all your work!!

  6. Great tutorial on setting up an email server! Really pushed this retiree to learn new things; SQL in particular.
    Is there a particularly good forum you recommend for PostFix questions?

    Thanks again,

  7. Thanks you for the great tutorial on ISPmail!
    I Think this is one of the best tutorial on the web you can find 🙂

  8. Greetings be to you Christoph Haas.

    Good to see your well-guided and informative website. I’ve really enjoyed the speed of your site, your detailed tutorials and your design simplicity.

    As I am a college student and fond of linux/open-source softwares– starting from hoby and a little step from newbie, I wanted to help my college with the introduction/installation of a server from the ground-up focusing on a wiki and wordpress+postfix-mail for the school [and capable to be upgradable in time]. As the main technical part has fall on to me as an initiator for this project, I would love to see your comments on this – especially the foundational considerations I should make.
    For now, my consideratiosn are:
    – Dell core 2 duo +2GB RAM [single desktop to run all the server combos, just a starting pc for now but upgradable when resources are available]
    – debian wheezy headless [for its long time support and stability]
    – mediawiki [for its support by wikipedia and all kinds of documentaiton]
    – wordpres [as a blog (one way info and comment on topics of the college’s posts; just like your website (wordpress being the font/main page and integrate/link the wiki from there)]
    – postfix+dovecot [as a mail-server]
    – [squirellmail/roundcube]—[for a webmail—but still have not decided between the two webmails; this is because I don’t know roundcube’s use would affect the other packages I install, especially when I don’t install nginx & ispconfig3; also I couldn’t find the roundcube package in the debian DVDs (my main source of offline repository)]
    – thunderbird [optional – for clients to access the mail server]
    – Apache [base for webserver]
    – mysql 5.5 [for wordpress & mediawiki databases]
    – php5 + phpmyadmin
    – samba [as a fileserver–to upload/download files]
    – calibre – headless [for book repository and sharing via web]
    – raw iptables rules [only allowing ports to server’s services; and no NATing]
    —-Securing the server services [not finished on its scope and the things I should put my hands on this….but I would like your help on this….]
    – git [I haven’t discovered its importance/importance for collaborative editing/version-control specially for my setting/environment (non-programming but active in literal works)]
    – the above configured server being at the center of the LAN, students+instructors will be able to access it via wireless AP[psk/AES] most of the time and rarely wired.
    — being a wireless is the only solution to accomodate all the students to connect to it using their laptops, but the security is my conern though the college has not much techies sofar this time!
    – the LAN will be off-internet [mostly working on the wiki and wordpress + books & thesis-paper upload/download]
    – My college is categorized/specialize all about Humanities studies, so it’s all about writing.

    Thanks in Advance.


  9. This is one of the best guides I have seen yet. Kudos and good luck with all your future endeavours.

  10. This is one of the best guides I have ever seen. Kudos and good luck with any future endeavours.

  11. The font size of the first paragraph on some of your pages is a bit smaller than the rest of the page. It makes the first part harder to read, but clicking around on the website, I get the impression it’s not consistent on all pages.

    Just wanted to give you a heads up.

    The information you provide is excellent. Thank you.

  12. Victor Carvalho

    Chis, thanks for your hard work. I learn a lot with you. Really, thanks for being an amazing professor!

  13. hi Christoph!
    i figured I’d give you a heads up on some of the older articles….since the relaunch of your site none of the block in the older articles work correctly. the information in them is the same color as the background and they are nolonger in mono font.

    I had previously used the Wheezy ISPmail tutorial to setup my mail server, and when I saw that you had finally got the Jessie version up I followed it and changed things where I needed to. Unfortunately I had to go back to the Wheezy tutorial to figure out some of the postconf commands that I needed to remove from the and files(most of this was clamav and AMaViSd stuff), which is where i saw that the code blocks were screwed up.

    The BIG thing I like about the Jessie tutorial is that i can use Roundcube now. I am SO glad you showed us how to do that!!!

    1. sentence is suppose to say: .since the relaunch of your site none of the ‘code’ block in the older articles work correctly.

      1. Christoph Haas

        Wow, I totally missed that. Thanks for your hint. When I relaunched this site I was pretty lazy and monkey-patched an existing theme. The first security update of course broke a lot of my stylesheets. Stupid me. I’m using proper child themes now and seem to have missed the styling of the Wheezy tutorial. Should be better now.

  14. Ludwig-Friedrich

    Hey Christoph,
    great work, especially on your ISPmail tutorial.
    But somehow I would wish someone made it work for a raspi. Of course that’s not really for professional matters in bigger companies but for a more home-office based small company.
    Do you know about a portation to this platform or maybe you’re planning to do the portation yourself?

  15. Rob McGee (/dev/rob0)

    Hey Signum, long time no see, hope you are well.

    Except for missing you, we in #postfix were well until this weekend, when one of many netsplits took out knoba! Please restart knoba, and come visit us sometime. 🙂

    Thanks, rob0


    Thank you, Chris
    This is an excellent tutorial. I had just finished setting up a postfix email server, I found many very good guides and followed some them, step-by-step and fortunately everything turned out fine.
    However, as good as they were, they didn’t explain why components were installed and what they did. This tutorial gave the big picture as well as the the fine detail, I wish I had found it earlier, it would have saved some angst!
    Cheers and thanks again

  17. Ratko Perlic

    Thank you for your great site.
    Is there any way to give donation for it?
    Is there any way to subscribe for new/modified content on this site?

  18. Hi Christoph,

    your ISP Tut for Debian 9.0 works without any restriction for Debian 10 too 😉

    Thank you very much for sharing your expertise.


  19. Steve Alderink

    Hey Christoph,

    Happy summer!
    Have you any experience with SYSLOG servers?
    I was thinking of setting one up and was curious if you have any opinions or tips.

    As always, I look to your site first because you are trustworthy and succinct in your presentations.

  20. Piraneo Giuliano Francesco

    Hi Christoph,
    your whishlist in Amazon is quite empty! 😱Really nothing that you like?

    1. Christoph Haas

      Heh, apparently my family has emptied the list for christmas. But my tinkering projects are never done. So I have “refilled” the list. 🙂 Thanks in advance.

    1. Christoph Haas

      Thanks, Jan. Yes, please find information on donating at the bottom left of the page. (You did not miss it. I just added it.)

  21. Hello
    After entering root@mail:~# swaks –to –server localhost in the console, I get:
    “=== Trying localhost:25…
    === Connected to localhost.
    <- 250-PIPELINING
    <- 250-SIZE 10240000
    <- 250-VRFY
    <- 250-ETRN
    <- 250-STARTTLS
    <- 250-8BITMIME
    <- 250-DSN
    <- 250-SMTPUTF8
    RCPT TO:
    <** 554 5.7.1 : Relay access denied
    -> QUIT
    <- 221 2.0.0 Bye
    === Connection closed with remote host."
    How do I change the /etc/hosts localhost mail
    so that localhost does not connect me to

    1. Christoph Haas

      I am not sure I understand the question. Your mail server reports its name during the SMTP dialog. And it responds to all interfaces so, and any other interface IP address would work. What is your expectation?

  22. Hi Christoph
    I have followed your excellent guides since Woody and I appreciate your work very much. Thanks. Hope you are working on Bookworm already… 😉
    Each 2cd years, after I have done my migrations, I always come back for some time to search for comments and answers that may have impact for my server too.
    I know this is WordPress, but does it have some sort of comment summary pages or other access pages to view the latest coments w/o searching too long inside the articles? I think to remember you had a ~last 10 comments sidebar assets in the past at least, which gave at least a short abbreviation.

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